Have 8630 just started overfilling clutch case and blowing out plastic timing plug. Drains all HD oil from trans case while overfilling clutch / Quod case.
There is a scavenge pump in the clutch housing that might have failed. It transfers oil back to the transmission. There is also a screen in the clutch housing that could be clogged. The pump is accessible from the hinge area. The screen is in the bottom of the clutch housing.